import 'package:flutter/cupertino.dart';

import '../../about/external/data/RoutineStep.dart';
import '../../about/internal/application/RoutineKind.dart';
import '../../about/internal/application/StepMode.dart';
import '../../about/internal/application/TextType.dart';
import '../../designs/buttons/Buttons.dart';
import '../../designs/input/CountStepper.dart';
import '../../designs/input/InputFields.dart';
import '../../designs/text/Text.dart';
import '../../utils/Colors.dart';
import '../../utils/CommonUtils.dart';
import '../../utils/Validators.dart';
import 'StepEditor.dart';

class StepEditorState extends State<StepEditor> {
  final GlobalKey<FormState> _formKey = GlobalKey<FormState>();

  final TextEditingController _title = TextEditingController();

  final TextEditingController _cue = TextEditingController();

  late RoutineStep _step;

  bool get _editing {
    return widget.step != null;
  }

  @override
  void initState() {
    super.initState();

    _step = widget.step == null
        ? _defaultsFor(widget.kind)
        : RoutineStep.fromJson(widget.step!.toJson());

    _title.text = _step.title;
    _cue.text = _step.cue;
  }

  /// A new step starts as the kind's most common shape, so most edits are
  /// just a title.
  RoutineStep _defaultsFor(RoutineKind kind) {
    switch (kind) {
      case RoutineKind.Workout:
        return RoutineStep(
            mode: StepMode.Reps,
            sets: 3,
            reps: 10,
            timerSeconds: 40,
            restSeconds: 60);
      case RoutineKind.Meditation:
        return RoutineStep(mode: StepMode.Timed, timerSeconds: 300);
      case RoutineKind.MustDo:
        return RoutineStep(mode: StepMode.Check, timerSeconds: 120);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: EdgeInsets.only(bottom: MediaQuery.of(context).viewInsets.bottom),
      child: Container(
        constraints: BoxConstraints(
          maxHeight: MediaQuery.of(context).size.height * 0.9,
        ),
        decoration: const BoxDecoration(
          color: colorSheetBackground,
          borderRadius: BorderRadius.only(
            topLeft: Radius.circular(28),
            topRight: Radius.circular(28),
          ),
        ),
        child: SingleChildScrollView(
          padding: const EdgeInsets.fromLTRB(24, 24, 24, 28),
          child: Form(
            key: _formKey,
            child: Column(
              mainAxisSize: MainAxisSize.min,
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                text(_editing ? "EDIT STEP" : "NEW STEP", 9, TextType.Bold,
                    color: kindColor(widget.kind), letterSpacing: 1.2),
                const SizedBox(height: 10),
                text(_title.text.isEmpty ? "What happens here?" : _title.text,
                    24, TextType.Light,
                    color: colorPrimaryDark, height: 1.2),
                const SizedBox(height: 20),
                inputField(
                  "Title",
                  _title,
                  hint: _titleHint(),
                  validator: Validators.title,
                  onChanged: _onTitleChanged,
                ),
                const SizedBox(height: 20),
                text("MODE", 10, TextType.Bold,
                    color: colorGrey2, letterSpacing: 0.8),
                const SizedBox(height: 8),
                segmentedSelector<StepMode>(
                  options: StepMode.values,
                  selected: _step.mode,
                  label: stepModeLabel,
                  onSelected: _onModeSelected,
                  activeColor: kindColor(widget.kind),
                ),
                const SizedBox(height: 8),
                text(_modeDescription(_step.mode), 12, TextType.Regular,
                    color: colorGrey2, height: 1.5),
                const SizedBox(height: 20),
                ..._numbers(),
                const SizedBox(height: 20),
                inputField(
                  "Cue",
                  _cue,
                  hint: widget.kind == RoutineKind.Meditation
                      ? "In 4 · hold 4 · out 4"
                      : "One line to read mid-step (optional)",
                ),
                const SizedBox(height: 16),
                _summaryLine(),
                const SizedBox(height: 20),
                roundedCornerButton(
                  _editing ? "Update step" : "Add step",
                  _onSave,
                  background: colorPrimaryDark,
                  icon: _editing ? CupertinoIcons.checkmark : CupertinoIcons.add,
                ),
                if (_editing) ...[
                  const SizedBox(height: 6),
                  Center(
                    child: textButton("Remove step", _onRemove,
                        color: colorDestructive, textSize: 13),
                  ),
                ],
              ],
            ),
          ),
        ),
      ),
    );
  }

  String _titleHint() {
    switch (widget.kind) {
      case RoutineKind.Workout:
        return "Deadlifts, plank, warm up…";
      case RoutineKind.Meditation:
        return "Settle, breathe, body scan…";
      case RoutineKind.MustDo:
        return "Make the bed, plan tomorrow…";
    }
  }

  String _modeDescription(StepMode mode) {
    switch (mode) {
      case StepMode.Timed:
        return "The clock runs down and the next beat starts on its own.";
      case StepMode.Reps:
        return "You end each set when the reps are done. Rest is timed.";
      case StepMode.Check:
        return "A task. You tick it; the clock records how long it took.";
    }
  }

  /// The steppers that apply to the chosen mode.
  List<Widget> _numbers() {
    final List<Widget> rows = <Widget>[];

    switch (_step.mode) {
      case StepMode.Timed:
        rows.add(_pair(
          countStepper("Duration", formatSeconds(_step.timerSeconds),
              onMinus: _onDurationMinus,
              onPlus: _onDurationPlus,
              canMinus: _step.timerSeconds > 5),
          countStepper("Sets", "${_step.sets}",
              onMinus: _onSetsMinus,
              onPlus: _onSetsPlus,
              canMinus: _step.sets > 1),
        ));
        break;
      case StepMode.Reps:
        rows.add(_pair(
          countStepper("Reps", "${_step.reps}",
              onMinus: _onRepsMinus,
              onPlus: _onRepsPlus,
              canMinus: _step.reps > 1),
          countStepper("Sets", "${_step.sets}",
              onMinus: _onSetsMinus,
              onPlus: _onSetsPlus,
              canMinus: _step.sets > 1),
        ));
        rows.add(const SizedBox(height: 10));
        rows.add(countStepper("Est. per set", formatSeconds(_step.timerSeconds),
            onMinus: _onDurationMinus,
            onPlus: _onDurationPlus,
            canMinus: _step.timerSeconds > 5));
        break;
      case StepMode.Check:
        rows.add(countStepper("Estimate", formatSeconds(_step.timerSeconds),
            onMinus: _onDurationMinus,
            onPlus: _onDurationPlus,
            canMinus: _step.timerSeconds > 5));
        break;
    }

    if (_step.mode != StepMode.Check) {
      rows.add(const SizedBox(height: 10));
      rows.add(countStepper(
        "Rest after each set",
        _step.restSeconds == 0 ? "None" : formatSeconds(_step.restSeconds),
        onMinus: _onRestMinus,
        onPlus: _onRestPlus,
        canMinus: _step.restSeconds > 0,
      ));
    }

    return rows;
  }

  Widget _pair(Widget left, Widget right) {
    return Row(
      children: [
        Expanded(child: left),
        const SizedBox(width: 10),
        Expanded(child: right),
      ],
    );
  }

  Widget _summaryLine() {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
      decoration: BoxDecoration(
        color: kindBackground(widget.kind),
        borderRadius: BorderRadius.circular(12),
      ),
      child: Row(
        children: [
          Icon(stepModeIcon(_step.mode),
              size: 15, color: kindColor(widget.kind)),
          const SizedBox(width: 10),
          Expanded(
            child: text(stepSummary(_step), 12, TextType.Medium,
                color: colorPrimaryDark),
          ),
          text("~${formatSeconds(_step.plannedSeconds)}", 12, TextType.Bold,
              color: kindColor(widget.kind)),
        ],
      ),
    );
  }

  // ── Handlers ──────────────────────────────────────────────────────────────

  void _onTitleChanged(String value) {
    setState(() {});
  }

  void _onModeSelected(StepMode mode) {
    setState(() {
      _step.mode = mode;
      if (mode == StepMode.Reps && _step.reps == 0) {
        _step.reps = 10;
      }
      if (mode == StepMode.Check) {
        _step.sets = 1;
        _step.restSeconds = 0;
      }
    });
  }

  /// Steps get coarser as the duration grows: 5s near the bottom, a minute
  /// once you are into meditation lengths.
  int _durationIncrement(int seconds) {
    if (seconds < 60) {
      return 5;
    }
    if (seconds < 180) {
      return 15;
    }
    if (seconds < 600) {
      return 30;
    }
    return 60;
  }

  void _onDurationMinus() {
    setState(() {
      final int next =
          _step.timerSeconds - _durationIncrement(_step.timerSeconds - 1);
      _step.timerSeconds = next < 5 ? 5 : next;
    });
  }

  void _onDurationPlus() {
    setState(() {
      _step.timerSeconds =
          _step.timerSeconds + _durationIncrement(_step.timerSeconds);
    });
  }

  void _onSetsMinus() {
    setState(() {
      _step.sets = _step.sets > 1 ? _step.sets - 1 : 1;
    });
  }

  void _onSetsPlus() {
    setState(() {
      _step.sets = _step.sets + 1;
    });
  }

  void _onRepsMinus() {
    setState(() {
      _step.reps = _step.reps > 1 ? _step.reps - 1 : 1;
    });
  }

  void _onRepsPlus() {
    setState(() {
      _step.reps = _step.reps + 1;
    });
  }

  void _onRestMinus() {
    setState(() {
      final int next = _step.restSeconds - 15;
      _step.restSeconds = next < 0 ? 0 : next;
    });
  }

  void _onRestPlus() {
    setState(() {
      _step.restSeconds = _step.restSeconds + 15;
    });
  }

  void _onSave() {
    if (_formKey.currentState?.validate() != true) {
      return;
    }

    _step.title = _title.text.trim();
    _step.cue = _cue.text.trim();

    Navigator.pop(context, _step);
  }

  void _onRemove() {
    Navigator.pop(context, false);
  }

  @override
  void dispose() {
    _title.dispose();
    _cue.dispose();
    super.dispose();
  }
}